Biofeedback

Does it work ?

Although some of the studies included in this summary indicate an improvement in pain relief and chemotherapy-related nausea and anxiety, these studies have not been independently replicated and have very small sample sizes. Evidence is therefore insufficient to document the benefits of biofeedback for people with cancer. Due to the difficulty in creating appropriate and credible placebo conditions double-blind studies are difficult to complete for this intervention.

Different types of biofeedback have been widely used in a variety of health care and rehabilitation settings. Reported effects from randomised controlled trials include a reduction in chronic pain2. Other reported benefits from case reports and uncontrolled trials include relief of stress and tension5.

Controlled clinical trials

Four controlled3,5,6,7 and one uncontrolled clinical trial9 have assessed the benefits of biofeedback for cancer patients.

A well-performed randomised clinical trial (RCT) assessed the effectiveness of electromyography (EMG) biofeedback, skin-temperature (ST) biofeedback and relaxation training in reducing the aversiveness of cancer chemotherapy (n=81)3. Results showed that patients who undertook relaxation training experienced a reduction in nausea and anxiety during their chemotherapy, when compared to the no-intervention group. Although the EMG and skin temperature biofeedback reduced levels of physiological arousal in participants, this did not alter the chemotherapy side-effects. Results suggest that relaxation training, but not biofeedback is effective in reducing adverse effects of chemotherapy.

A small RCT investigating the effectiveness of relaxation training supplemented with visual and auditory electromyography (EMG) biofeedback signals found a reduction in pain intensity in people with advanced cancer (n=12) compared to the control group (n=12)5. This study is limited by its small sample size.

Another small RCT explored changes in the immune system and psychological profile of women with breast cancer who had recently undergone radical mastectomy (n=13). Patients were randomised to either an intervention group who were trained in relaxation, guided imagery and biofeedback over a 24 week period or a waiting list control. Results indicate that relaxation, guided imagery and biofeedback interventions can be correlated with immune system and anxiety measures6. Due to the small participant number and the use of a multi-modal intervention it is impossible to draw conclusions about the benefits of biofeedback.

Another small RCT investigating the effectiveness of electrodermal (skin conductance) and electromyographic (EMG) biofeedback for people with advanced cancer found reduced pain during the intervention (n=12). However, only six of the 12 participants completed the trial. Five participants died and one moved away from the area. The study results are limited by the small sample size and lack of an adequate control group. The study utilised an ABA single-subject design, where subjects acted as their own controls.7

There is insufficient evidence from one small uncontrolled feasibility trial (n=12) that biofeedback (heart rate variability) or relaxation is beneficial as a coping strategy for children with cancer experiencing procedural distress.9 Although participants demonstrated an improvement in heart rate variability coherence scores in sessions 3 and 4 (p<0.05), the study is limited by its small sample size and lack of control group.

Burish TG and Jenkins RA. Effectiveness of biofeedback and relaxation training in reducing the side effects of cancer chemotherapy. SO: Health Psychology: Official journal of the Division of Health Psychology, American Psychological Association. 1992; (1): 17-23.

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